Stepped Disconnection-Contributing AgRuIr Nanocrystals with Turtle Shell-Shaped Oxide Layer for Acidic Water...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Designing efficient catalysts for water oxidation is crucial for sustainable energy technologies.
• Spatial symmetry and electronic properties of catalysts significantly impact their performance.
• Localized chemical environments are key to synergistic catalytic activity.

Purpose of the Study:

• To develop novel ultrafine AgRuIr nanocrystals with engineered stepped disconnections.
• To investigate the role of stepped disconnections in enhancing water oxidation catalysis.
• To optimize catalyst design for improved activity and durability in proton exchange membrane water electrolysis.

Main Methods:

• Rapid non-equilibrium crystallization using medium-temperature alcohol-assisted thermal reduction.
• Synthesis of ultrafine AgRuIr nanocrystals with controlled stepped disconnections.
• Characterization of atomic structure, electronic properties, and catalytic performance.

Main Results:

• AgRuIr nanocrystals with dense stepped disconnections were successfully synthesized.
• Atomic Ag preferentially located at line defects, stabilizing stepped disconnections.
• The catalyst exhibited an ultra-low overpotential (188 mV@10 mA cm^-2) and high efficiency (42.81 kWh/kg H₂).
• Enhanced H₂O adsorption and activation kinetics were observed due to unique oxide layer structure.
• Ag-pinned dislocations inhibited Ru/Ir leaching, ensuring operational stability.

Conclusions:

• Stepped disconnections provide a powerful strategy for designing advanced water oxidation catalysts.
• Engineered stepped disconnections simultaneously enhance catalytic activity and durability.
• This work offers a new paradigm for next-generation proton exchange membrane water electrolysis catalysts.